Fan units of the above referenced kind are used as a part of a filter fan for industrial installations such as control panels. The fan units can be configured as a blowing fan unit as well as a suction fan unit. The known fan units for fan filters normally have an axial fan wheel as a flow drive of the fan unit and are screwed to the filter frame of the filter fan via a mounting flange of the fan unit housing. A protective grid is screwed to the fan unit housing as a protection of the fan unit. The disadvantage of such fan units is that they have a large overall height and are expensive to manufacture. In addition, they have to be mounted on the filter frame in several work steps with tools, and changing the conveying direction is only possible by means of an expensive mounting procedure. During maintenance of the filter fan, the fan unit, as well as the protective grid has to be dismounted and again mounted afterward.
The object of the invention is to provide a solution which allows the manufacture of a more compact fan unit in an easier and less expensive way, which provides high efficiency and is particularly easy to install in the filter fan as a blowing as well as a suction fan unit, and which can be dismounted for the maintenance of the filter fan in a particularly easy way.